Dynamo-electric machine.



A. A. E. STERZING.

DYNAMO ELECTRIC MACHINE.

APPLICATION FILED MAR.25. I914.

1,299,053, d Patented Apr. 1,1919.-

3 SHEETSSHEET I.

'l V/YNASSES: J, W [NI/EN TOR. i/Md BY 7W WIKM/ATTORNEY A. A. E. STERZINGK DYNAMO ELECTRIC MACHINE.

APPLICATION FILED MAR. 25. 1914 "Patented Apr. 1, 1919..

' 3 SHEETS-SHEET 2.

a444 ATTORNEY.

A. A. E. STERZING.

DYNAMO ELECTRiC MACHINE.

APPLICATION FILED MAR. 25. 1914.

Patented Apr. 1, 1919..

3 SHEETS-SHEET 3 [NVN TOR;

A TTORNE Y.

1;] TNESSES ALBERT A. E. s'rnnzm or NEw'YoRK, N. Y.

DYNAIMO ELECTRIC MACHINE.

' Application filed March 25, 1914.' Serial No. 827,043.

To all whom it may concern:

Be it known that I, ALBERT r INC, a subject of the King of Great Britain,

and ELIBSldBD of the city, county, and Stateof New: York, have invented certain new and useful Improvements in Dynamo-Electric Machines, of which the following is a specification.

This inve electric induction and particularly to those wherein the electric current is caused to flow continuously 1n the same direction.

Primarily, the invention has for its object to produce an improved machine of this character composed of but a few simple parts, easilyconstructed and readilyassembled, and forming together a structure dlstinguished by its strength, compactness, 20

thorough efiiciency, and economical operatiOIL- I 'A secondary ob ect is to provide for the machine a field-magnet unencumbered with I the usual polar fittings and yet capableof yielding a copious supply of lines of force evenly distributed throughout.

A furtherobJect 1s to combine with the;-.-

I midfield-magnet a symmetrical armature which is correctly balanced electrically as well as in mechanical respects, and has a large effective area compared withthe diameter of the magnetic shell housing the same. p

Another object is so to construct, proportion, and mount the said armature as to enable it to perform its work within a relatively narrow gap between the polar sur- '-faces of the field-magnet, and at the same 'time to provide it with adequate means of ventilation, so that while there will be no diminution in the weight of the metal to interferematerially withthe magnetic flux, the armature willbe keptsufliciently 0901 always to prevent generation of excessive heat therein with consequent resistance and waste of energy. v v 1 Still another object is to equip the armature with a novel set or series of oonveyers, distributers, conductors, and collectors of electric current which are adapted conjointly to lead, gather, and transmit thecurrent constantly in the one direction through the shortest practicable path from the negative to the positive elements f the machine, thereby avoiding reversals, insur ing an ample electrical output in a brief A; E. slam.

'tio'n relates generally to ma-= chines working on the principle of magneto- J ';-rusal of the descriptive matter hereinafter period of time, andso favoring the vproduc-v tion of current that, being given the requ irapid cutting of lines of force, the machine may be depended on to operate successfully at a high voltage: v e Other objects and advantages ofthe in-- vention will be readily perceived upon pe incorporated.

Specification of Lctters Patent. Patented Apr. 1, 1919. v

With the said objects in view, the invention consists of. the new and improved ele ments, combinations, suboombinations, and

arrangement of parts herein shown and described in their preferred embodiment, especial reference being made to the characteris- Among other peculiar features thereto aptic features thereof presently to be outlined and further set out in the SllbJOlIlGCl claims.

lar field-magnet'hollowed out from its inner circumference to form two continuous surfaces of opposed'polarity aflordin'g an-inter-- vening gap adapted to receive the rim of -a discoidal armature.

A subsidiary feature of the invention con- :sists in making the field-magnet relatively massiv in the reglon of the polar surfaces, 1 on opposite sides thereof, where the arm'ature revolves.

Another feature relatingtothe field-magnjet res ides'in the winding of the magneticwire-co1ls within the same in planes parallel to that of'theiarmature, on opposite sides of the latter. v

According to anbther'feature of the invenQ tion, the rim ofthe armature its-equipped laterally with current conductors cons1sting' of short sectionsof wirespecially formed outer ends to provide air gaps therebetween.

' The same element, inaccordance with still another feature of the inventlon, carries an for close juxtaposition at their inner ends, I I butseparatedfrom one another at'their g loo to the ventilation of both the field-magnet and'the .discoidal armature, to the current" collectorsandtransmitters. and to certain structural details,'a ll of which will be easilyfl.

identified as the Specification proceeds,

operation of the machine will now be described with reference to the drawings hereto annexed, where1n- Figs. 4 and 5 are detached side views ofbare conductors seen in side elevation on the sections of armature represented by F1gs. 6 and 7,,respect1vely;

Fig. dis a fragmentary view, illustrating the armature as provided with single layers of current conductors;

Fig. 7 is a similar vlew, showing the armature equipped With conductors dlsposed 111' double layers;

Figs. 8 and 9 are rear or exterior views of similarly positioned halves of concentric annular brushes that are provided on the opposite sides of the armature;

Fig. lO is a. peripheral view of the segment of outer brush shown in Fig. 8, looking downward from the upper edge thereof;

.Fig. 11 shows-in diametrical transverse section the segment of inner brush represented'by Fig. 9, as it appears looking up inside the same and Fig. 12 is a side elevation of the armature denuded of its wire equipment, save two small segments thereof, which are shown respectively covered with current conductors of the two difierent forms before mentioned, In the form herein shown, the body of this improved machine consists of two annular iron castings 21, 22, which are duplicates one of the other, and therefore can be made conveniently from a single pattern. These castings, as seen in Fig. 1, are substantially U-shaped in cross-section, though they are held up sidewise, with their closed, convex ends turned oppositely outward, and consequently with their sides, which are of difi'erent lengths, also in opposed relation. The

longer sides are made to abut edgewise against each other as at 23, on a median line of the machine, at which place the opposed parts are provided with paired lugs 24, adapted to receive cross-bolts 25 between them, by means of which the two castings are secured firmly together. The shorter 'sides terminate each at some distance from the middle 11116 23, leaving a gap 26 between them, which communicates with the vacant spaces or recesses 27 that arejinclosed withtip the conjoined pair of U-shaped castings. hus constructed and assembled, the paired castings 21 and 22 constitute a magnetic shell or field-magnet substantially in the form of a hollow ring which is open longitudinally' throughout its inner circumfer ence, and the concave portion of which affords a circular channel wherein a diskarmature (hereinafter described) is adapted to rotate.

In the dynamo-electric machine of the' form herein set forth, the field-magnet is meant to be the stationary member, and therefore the said annular castings are supported by and rest upon four legs 28, located as usual on opposite sides of the machine. These supports 28 may be produced integral with the field-magnet, and fastened in' any 1 approved manner to the floor or baseupon which the machine is set up for operation. Flgs. 1 and 2. No special foundation need i be provided for the aforesaid field-magnet,

thereof, which is quite thickand compact,

compared with its outer circumferential por- .tion, as shown in Fig. 1. The special object aimed at is to provide in the vicinity of the armature a magnetic element of suitable permeability, capable of generating a bounteous supply of lines of force streaming in a continuous current. The heavier mass of the iron, it will be observed, borders the gap 26, the. sides of which are designed to afford continuous polar surfaces. The sides of the gap, characterized each by width and continuity, form a large magnetic field for the armature, and being massive, they afford the requisite depth of polar areas without the additionof such pole pieces, cores, or extensions as-are ordinarily employed.

The gap 26 and recesses 27 communicate with one another inside the field-magnet and together constitute one continuous annular opening, which is T-sha'ped transversely and p the vertical part of which (as seen in Fig. 1) presents a relatively narrow space for the projecting rim of the armature, while the horizontal portion forms coupled compartments by the sides of the latter, that are partly utilized for the reception of magnetic wire-coils 31. These coils may be laid conveniently in annular channels 32, at the bottom of their respective compartments, as the said Fig. 1 shows. The coils 31, it will be noted, are placed in their channels 32, in planes concentric with the axis of the fieldmagnet or magnetic shell, and parallel to' the plane of the armature, on opposite sides of the same. Provision is thus made for wiring the field-magnet in proximity to the poles thereof. It is understood that the flow of magnetic lines of force should be brought up to and maintained at the correct density betwee'nthe poles of the field-magnet here the rim of the armature is revolving, that there may not be undesirable fluctuations, nor eddies, in'the electric current, but, on the contrary, to insure at all times a continuous current of uniform strength, capable of developing steadily the desired degree of electromotive force. 1 i r v Centrally of its circumferential part, and

directly opposite the edge of the armature within the same, the field-magnet is provided with a series of transverse slots 36, which 'communicatewith the aforementioned recesses 27 and gap 26, and thus afiord a means of ventilation for the interior of the magnetic shell and the inclosed armature.

. These slots, preferably, aremade to cross the middle plane of the combined field-magnet and armature, at regular intervals between the lugs and bolts that unite the two iron castings 21 and 22. Being elongate and narrow, they do not impair the activity of the the air that iron, norv permit too great a disturbance of opening (26, 2 no matter how fast or how slow the armature is revolved. The slotted circuit.

outer part of the'field-magnet, it will be observed, has little if any weight to carry, and therefore it may be made as thin as is consistent with the structural strength of the machine, since there is a sufficiently good magnetic conductivity provided, otherwise,-

due to the position of the armature in the In accordance with common practice, the machine herein described, when used as a generator, will be supplied with an excitlng currentfrom the .outside, which may be derived'from any convenient source.

By preference, the armature is of the disk type, as previously mentioned, and it constitutes the rotary member in the exemplificationof the invention herein expounded. The body of this armature, 1n the form represented by Figs. 1, 2, 6 and 7, comprises two.

distinct parts, to wit, a solid hub-and-web portion 41, and a radially-perforated por-' tion 42. As shown, these parts may be cast integrally together, and they are mounted so as to turn in a vertical plane, on a horizontal shaft 43, to which they are keyed", either to rotate the same or to be revolved thereby,

depending .on "the function eventually discharged byv the machine, that is, whether it be that of a generator, or motor, or converter.

- In any event, the body of the armature and its shaft connection are made sufliciently substantial and durable to resist properly the effects of both the turning moment and thecentrifugal force which they will have towithstand, whether they be formed integral or composed of two or more pieces rigidly interconnected.

Standards 45, with bearings 46 at their upper ends, are placed one at each'side of asses through the T-shaped the field-magnet, 'to support the said shaft and armature thereon. The shaft is passed through and across the annular field-magnet, so that it coincides with the transverse axis of the magneticfield, while the armature is mounted so as to revolve centrally therein,

with its rim projecting into theflTi-shaped' opening composed'of the 'before mentioned gap 26 and recesses 27, where the magnetic lines of force are taken up by the armature on lines parallel with the fieldsaxi's but in a v a peripheral plane. The standards45 are located close to the sides of the field-magnet, and consequently that part of the shaft. 43 which extends between the bearings 46, and

carries the armature, is short and not liable to fleXure. Moreover, a pair of collars 47 is provided on the same part of the shaft, which collars abut against the'inner sides of. the bearings 46 andcoiiperate in maintaining the shaft rigid, besides preventing endplay thereof transversely of the machine.

The collars 47 are held on't-he shaft by means of set-screws 48, which latter admit of the shaft being longitudinally adjusted, in such a way as to center exactly the armature within the field-magnet and "brin it into perfect electrical as well as statical alance, assuming, of course,there has been a symmetrical distribution of the armature wires all around the shaft, in the manner about to be described. No difficulty will be experienced in alining the shaft or keeping it in line, owing to its separable bearings and standards,

which are secured in place independently of the field-magnets supports. The standards are sufiiciently narrow, as shown by dotted lines in Fig. 2, to offer practically. no obstacle to reaching the interior of the field-mag net when it becomes necessary to effect therein some slight repair of the inside parts.

,Both standards or either of them may be -quickly removed, also, if-desired, to afford full access to the internal parts and give the machine a general overhauling.

The rim of the armature is preferably made of cast-steel or soft iron, and forms theacross the ga 26 in the field-magnet, extending outward y into the recesses 27, and inwardly to a plane more or less closely circumscribing the inner periphery of the united annular.U-shaped castings 21, 22. As the v polar surfaces of the field-magnet borderin the gap 26 are offair width and the rim 0 an armature of commensurate capacity with in a magnetic shell of comparatively small diameter and to that extent is favorable to the rapid and economic production of an electromotive force intended to furnish the requisite torque with a modicum of electric current.

Short sections only of copper wire are needed for the current conductors 51 and 52. As illustrated in Figs. 1,2 and 12, the

several wires or wire sections 51, 52, are

' laid fiat against the sides of the armature the outer ends of both scriesof wires 51 and ,52 spaced apart to provideair-gaps 56 between them, as seen within the broken porrim, facing therewith the opposite polar surfaces of the field-magnet, within the gap 26. The inner ends of all these wires are made to adjoin one another near the inner .edge of the rim 42, from which they are separated by rings 54, of brass or other non-magnetic metal, recessed therein (Fig. 1). At their outer ends, the wires are also isolated from the armature by similar non-magnetic rlngs 55, likewise embedded laterally 1n the outer edge of the rim. The latter-named ends of the wires, however, may or may not be placed close together. In the smaller-sized machines, it is deemed preferable to have tion of Fig. '2 and in the upper part of Fig, 12. 'In the larger machines, on the other hand, it is preferred to have the outer ends of the said wires 51, 52, nearer to one another,

as shown at the bottom of Fig. 12. The op:

posite ends of the wires are respectively soldered to rings 61, 62, 63 and 64:, hereinafter described. The soldering should be effected while the wires are under tension, that is, held taut with the aid of pliers or some other suitable tool. When the wires are being applied to the latter-named rings, the interstices caused by the removal of the insulation from the several wires at the fastening points thereof are filled with solder, which is shaved off to present a smooth surface on each side of the rim 12, as will be understood.

Figs. 1 and 5 illustrate what are considered the two best shapes of wire to apply on armatures of all sizes, dividing the latter into large and small, respectively. Both forms of wire shown, it will be observed, are gradually flattened and correspondingly expanded in opposite directions a greater or less distance from their upper portions down to their lower ends. The wire represented by Fig. 1 is thus made flat'and spread from the point marked 57, thereby enabling a number of like wires to be placed side by side, with their flattened portions directed edgewise against the armature, in such a manner that the several wires Wlll be ad] acent to one another at the inner edge of the .rim, but will have the intervening air-gaps bottom part of Fig. 12, as previously stated.

This is believed to be the most practicable mode of construction and arrangement to adopt for the current conductors on the armature, where the density or compactness of the copper wire equipment becomes a desirable factor or an important consideration. Wires of this improved manufacture can be laid in practically perfect continuity upon both sides of an armature, since the ends of all the wires, because of their peculiar configuration, will naturally lodge side by side on the opposite lateral surfaces of the rim, converging thereon. in proper ratio to the diminution of their superficial areas edgewise, and forming an unbroken assemblage oneach side of the armature. As best seen in Figs. 6 and7, the rim 42 is slightly hollowed slantingly from its outer edge inward on both sides, to afiord suitable depressions wherein the flat ends ofthe wire are nested with heir expanded edges transversely disposed and projecting outward, so that the sides of the Wired rim, which are to face the poles in the gap 26 of the field-magnet, will be substantially straight, whether one or more layers of wire be used, for instance, in

either of the ways suggested in the figures last named.

Outwardly, the ends of the two series of wires 51 and 52 are also united by solder v to the contiguous sides of two pairs of rings 61, 62, and 63, 64, which perform the functions, respectively, of distributing the current ,to and collecting it from the aggregate of conductors on the armature. Hence, these two pairs of rings will be referred to hereinas current distributers and current collectors.' For-the purposes of this specification, it will be assumed that the inner rings 61 and 62 are the distributers, and the outer rings 63 and 64 the collectors, of the electric current. The four rings 6164. may be made of copper, aluminum, or steel, each preferably in one piece. In the formof the invention shown, these rings cover up completely both ends of the two series of wires 51 and 52, on the opposite sides of the armature rim, to which they are secured, as also with one another in pairs, by means of brass bolts 65. As Fig. 1 shows, the bolts- 65 are sunk at both ends deep into theopposed inner sides of the said pairs of rings, that they may not leave projections on the outer faces thereof, which it is desired to keep smooth throughoutfor a more extended con-- tact with the brushes hereinafter'described. Meanwhile the wires 51 and 52 are securely bound in place and Well adapted for the discharge of their function as armature condoctors.

Several advantages accrue from theus'e of the special forms of wire conductors applied to the armature as above described In the first Place, the wires closely embrace the sides of the armature rim, against which they are firmly Held by and between the vathe armature, on both'sides, instead of being pulled off 'by the magnetic drag prevalent in some other machines..' The result-is a'free,

unobstructed field wherein the rim of the armature remains unimpeded (Wliile cutting the magnetic lines of force.

v Another gain resulting from the employment oftheconductors 51 and 52 is found in that only asmall amount of copper-is actually used for the armature winding or rather covering, on account of the short path aflorded to the electric current between the distributer and. collector rings. Besides the reduction in the elementof cost, by using a less quantity of copper and a larger proportion of iron in the armature, a stronger magnetic field is obtained. The requisite amount of copper is had, as will be understood, by gaging the cross-section of the conductors to suit, and if more is desired for any particular case, one may resort to the expedient of using two or more layers of,

mm as suggested in Fig, 7 according to the purpose in view.

" By disposing the copper wires laterally over the rim of the armature, and locating them between continuous polar surfaces as herein shown, a full working length of the current conductors is obtained within a small compass. and their longitudinal measurement will not vary very much for any size of machine the circumferential increase of the armature rim calling mostly for a larger number of conductors of thestandard len th.

The current conductors herein disclosed further permit the grouping together in one compact mass, of several elements which otherwise would be separate and hence would occupy more space. Thus, thearmatiires rim or effective core 42, the aggregate of Wireconductors '51 and 52 thereon', .the 'two pairs of non-magnetic rings- 54,-55, Isolating the wire ends from the rim, as also both pairs of current distri'buters 61, 62'a'nd cue rent collectors 63, 6e, over the-wire ends, and the web-and-hub portion 41 keyed to -the shaft 43, are all united to form asinglri; .75.

member, which practically may be consl'de ered as the armature, taken as awhole. This construction is possessed of 'great strengthgl. and enables the armature with its adjun s; or accessories to be lodged afs'a' unit and? within limited quarters in the very center} of the magnetic field. 1

. In order to guard-against more or less ,jectionable or needless pulsationsin the current, the polar surfaces of the field-magnet are divided into obliquely-disposed sections 71, produced by grooves 72 and 73.. As

shown in Fig. 2, the grooves 72 are concentrio with the rim of the armature, whereas. the grooves 73 run crosswise thereof and are I substantially tangential to the armature shaft. Now, if the armature is revolved in either direction, it will be seen thatthe wires in the series 51 and 52 thereon are positioned angularly with relation to the'sides of the sectioned polar. surfaces, and consequently will be enabled at all times to snap the lines of force readily, thereby securing a smooth fiow of electric current. 1 y

A means of ventilation. for the armature is incidentally afforded by the above-mentioned grooves 72, 73, which constitute as many avenues ofescape for the heat arisingfrom the rapidly revolved armature and accumulating in the gap 26 or about the pairs of rings 61-64=. Proper ventilation and 105.

cooling of the armature are further provided for by forming the rim 42 thereof with radial passages 74, running inward from a peripheral groove 75in the outer edge of the rim and curving out alternately toward the 110 opposite sides of the latter, as at 7 6, 77. See Figs. 1 and 12. The combined passages 74, 75, and gap 26 lead from the center of the machine to the recesses 27 beyond them, and

thence out by way of the slots 36, the rapid 115 revolution of the armatures rim causing a fan-like draft therethrough, which carries away the cir'cumambient air and immediately relieves the armature from the incipient heat.

The previously mentioned current distributing and collecting rings 61-64, are preferably attached to the rim of the armature so as to rotate with it sidewise. Being securedjon the sides of the armature, as shown, 125

they are not subiect to any prejudicial ac- 'ti'oniof the centrifugal force developed at the outer edge 'of the rim. It is deemed advisable to make these rings of soft iron or steel instead of copper. However, they may be 130 that all of the Wires 51, 52, should have in dividual contact at their ends with both pairs of these rings, so there will'be no bythe said hollow portion and its said projections, gives best results when made of neutral wire, and'none poorly connected in the circuit. The two pairs of rings, positive and negative respectively, form an integral part of the armature circuit, the electric current being received by them directly from the conductors on the armature and supplied to theexternal circuit, or the reverse. The said two pairs of rings, it will be noticed, are kept well apart on opposite sides of the machine, where a high insulation can easily be effected.

Annular brushes 81,82, 83, 8 1, are placed in sliding contact with the aforesaid rings 61, 62, 63, 64, and held laterally thereagainst bv certain devices next to be described. Figs. 1, 2, and 8 to 11. By preference, the

rear or outer portion of these brushes is made hollow so as to-inclose a core 85, as indicated in the sectioned parts of Fig. 11, and their face or inner portion is slotted at various angles transversely to produce therein an endless, circular series of teethlike projections 86. The core may be of steel, but the dentate shell thereover, formed either copper or aluminum, the latter being preferably copper-plated. It will beseen that the projections 86 are well adapted, by virtue of the induced air-currents during the rotation of the armature, to dissipate rapidly the heat caused by contact of the brush with the adjoining current distributer or current collector, whichever it may be. A

brush of this kind can be .manufactured.

cheaply, and'therefore may be replaced often at small expense, if it should wear out fast. It is expected, of course, that the toothed shell will become worn sooner than the broader-surfaced distributor or collector ring with which it is to be in frictional engagement, but its relatively-low cost admits of more frequent renewals.

Like the distributer and collector rings to which they are respectively assigned, the said annular brushes are arranged in pairs, corresponding to the paired rings in size and location. Accordingly, the brushes 81 and 82, apportioned to the current distributers 61 and 62, are placed exteriorly thereof within the inner periphery of the annular field-magnet, and the brushes 88, 84, allotted to the current collectors 63, 6%, are similarly positioned contiguous thereto inside the recesses or compartments 27 of the castings 21, 22. The two pairs of brushes are suspended, each in its proper vertical plane as illustrated in Fig. 1, by means of a circular series of knobs 91, provided thereon and engaged by adjusting members 92. The

knobs 91 may be of steel or wrought iron I and-Welded or riveted to the aforementioned "core 85, Fig. 11. The adjusting members 92 are slidable horizontally in the direction of their length and are disposedin concentric series (Figs. 1 and 2) respectively suppredetermined points around the inner. borders of the field-magnet, on opposite sides of the armature. Bearings 97. are formed at regular intervals transversely of the frames 93, for the inner seriesof adjusting members, and similar bearings 98, wherein to fit the adjusting members of theouter se-- -ries, are provided in the sides of said castngs.

Each adjusting member aforesaid comprises, as shown, a brass sleeve, numbered 92. The several sleeves are urged inward, against the pairs of rings 6164 and over the slightly conical knobs 91 thereof, by means of plugs 103 and spiral springs 99, coiled around said sleeves and plugs and anchored at their inner ends, either to one of the frames 93 or to lugs 100 on the sides of the field-magnet, according as the adjusting members belong to the inner or to the outer series. At their outer ends, the said springs are engaged each by two pins 101 and 102, passed transversely through the plug 103, entering the latter from the outer end thereof. These pins pass also across the spirals of the spring, so that either of them can be grasped by the hand and turned either forward or back. Thus, the pins 101 and 102 may be used for advancing or retracting the two series of adjusting members as needed, to make or break contact between the brushes controlled thereby and-the corresponding distributer or collector rings. A few convolutions of the springs 99' are placed under compression between these two pins, so that the latter may not be shifted along the spirals of the former, through vibration of the brushes 83, 81-. l The compressed part of each spring will thus have practically the effect ofa lock-nut on the corresponding adjusting'member, and the several springs, which obviously are subjected to less tension at the top than at the bottom of the machine owing to unequal distribution of the weight of the suspended brushes, can all be adjusted to meet the vari- These disks or counterweights 106 are adapted to ride loosely on the compressed coils of the spiral springs 99, between. the" pins 101 and 102 of the plugs'103, a recess 107 in each disk allowing the pin 101 to be engaged by the spirals of-the springth erein .when it is desired to regulatethe tension of. the latter for the purpose before mentioiied;

Tension springs 111 may be substituted for the counterweights 106 above described;

if desired. As shown at the loWer'left-hand corner, of Fig. 1, springs of this type could be at ached by one end in grooves 112,

Weights for all motors designed for purposes of travel, for instance, those operating. cars 'or vehicles of various descriptions, on railways, tramways, speedways, etc. 3 It is now apparent that, arranged asdescribed and shown, the several adjusting members can be manipulated so as to bring the appropriate degree of pressure -to bear on the brushes and the contacting rings 61 6 1, and insure their smooth operation. perfect control is provided over the individual brushes, and by adjusting them so as to press evenly always upon the thereto related rings, the wear will be equalized, no sparking will occur, and thedistortion of the brushes commonly due to the cutting of ruts or hollows therein by unequal friction will be avoided. 7

As illustrated in Figsl and 2, the inner brushes are joined in the electric circuitby' wires 115, lodged and'soldered in the semicircular or C-shaped pockets 116, provided on the outside of each brush, between the knobs 91 thereof. The wires 11 5 are thence doubled up, led to, and attached to copper rods or wire-cables 117, 118, located one on each side of the machine. These. rods form each an open circle on the opposite sides of the field-magnet; from which they are supported by brass staples or eye-screws 119. They constitute the negative terminals in the machine shown, and are suitably connected with the main wires of the electric circuit.

The said-wires are given a relatively large contact with the inner brushes, for the pur pose of distributing the electric current quickly, as well as evenly. Separate wires like these are preferred to a direct connection of the said terminals with the inner brushes. The terminal rods 117 118, it will be understood, have each one dead "end, and are wired to, or in the external circuit in such a way that all the induced electromotive forces are caused to act in the same direction. These two rods or wire cables are'united at some distance from the ma chine, to constitute the regular negative sec tion of the circuit, which is divided simply for the purpose of placing therein the two brushes that'arejincontact with the inner pair 10f rings onfthe', opposite sides of the armature.

A third rod and form as the rods or cables 117,118, above cable of same metal referred to, constitutes the positive terminal in the particular species ofmachine represented in' the accompanying drawings.

by Figs. 1 2, and 3. Outwardlygrooved insulators' 122, provided at various intervals on some of the paired lugs 24, afford the proper support for the rod 121, which is further secured in position by the wiring 125, as indicated in Fig. 3. Electrical connection between the positive terminal and the outer brushes 83, 8d, is effected by means of a series of short wires 126, each soldered centrally of its length in a groove 127, formed around thesebrushes (Figs. 1 and 10). The wires 126 are thence led outwardly to the rodj121, first by crossing the ends of adjacent wires, and then passing the crossed ends thereof through alternate slots of the'series 36, in the middle circumferential plane of the field-magnet.

The herein described invention in its broader aspects is not limited tothe precise construction set forth and illustrated, nor to any particular construction by which the same" has been or may be carried into effect,

. as manychanges may be made in the details outwardly between the massive parts there of beyond said coils, and axially extending brushes engaging the projecting portion of said armature.

This last named terminal rod-is preferably, located so as to encircle the field-magnet, centrally thereof, in the manner brought out 2. A dynamo-electric machine comprising ahollow annular field-magnet composed of longitudinally divided halves having relatively massive portions held apart and thinner portions joined together around the same, magnetic coils placed adjacent to said massive portions, a laterally wired discoidal armature constructed so as to make it project past said coils and bring its rim into a space intermediate of saiddivided halves, and axially extending brushes engaging the proj ecting portion of said armature.

3 A dynamo-electric machine comprising an annular field-magnet having bare polar surfaces of substantially equal magnitude opposed one to the other, a discoidal armature with a rim carrying series of wires radially disposed between said surfaces, magnetic wire coils surrounding the fieldmagnet laterally of said armature rim, and axially extending brushes engaging the armature transversely of said wire series.

4. A dynamo-electric machine comprising a hollow field-magnet of annular form composed of similar halves joined centrally together at the periphery, magnetic wire coils wound interiorly around said field-magnet on opposite sides of its central joint, a dis coidal armature mounted in the field-magnet with its rim projecting beyond said coils. into a gap between said halves, and axially extending brushes engaging the projecting port on of said armature rim.

i 5. A dynamo-electric machine comprising line thereof, magnetic wire coils in said channels, and a discoidal armature having a rim covered with separate wires centrally located within the field-magnet.

7. A dynamo-electric machine comprising an annular field-magnet hollowed out laterally from its inner circumference, oppositely located channels formed inside of said field-magnet, a laterally wired discoidal arina-ture projecting into the hollow of the field-magnet midway between said channels, magnetic wire coils in the latter positioned withinthe periphery of said armature, and axially extending brushes having peripheral engagement with the armature beyond said coils. w,

8. A dynamo-electric machine comprising an annular field-magnet hollowed out from its inner circumference to .form a gap eX- tending outwardly theiefrom and a recess transverse to the same, said gap. and recess formin together an opening substantially T-shaped in'the field inagnets cross-section, oppositely located channels farmed within said recess, a discoidal armature projecting through said gap, groups of separate wires radially disposed on both sides of said armature, magnetic wire coils wound annularly about the field-magnet in said channels, and axially extending brushes engaging the projecting portion of the armature.

9. A dynamo-electric machine comprising a field-magnet having transverse circumferentially arranged slots and opposed continuous polar surfaces sectioned by intersecting grooves communicating with said slots, combined with a radially-wireddiscoidal armature mountedto revolve between said polar surfaces with its rim directed edgewise relatively to said slotsand sidewise with relation to said grooves.

10. A dynamo-electric machine comprising an annular field-magnet hollowed out from its inner circumference toprovide opposed polar surfaces with a gap therebetween, grooves sectioning said surfaces on opposite sides of said gap, and outwardlyleading passages communicating with both gap and grooves, combined with a laterallywired discoidal armature arranged to revolve with the opposite sides of its rim facing the polar surfaces within the length of said passages.

11. A dynamo-electric machine comprising an annular field-magnet formed with 0pposed polar surfaces and a circular series of parallel ventilating passages disposed in a diametrical direction, combined with a dlSCOlCliLl armature having radial slots in communication with said passages and electi'ically wired on opposite sides of its said s ots.

12. A dynamo-electric machine comprising an annular field-magnet hollowed out from its inner circumference to provide op posite poles and formed with transverse circumferential passages suitable for diametrical ventilation, combined with a discoidal arposite sides of the groove therein.

14:. In a dynamo-electric machine, a discoidal armature formed with a longitudinal groove around its periphery and with radial slots in its rim leading to said groove, combined withelectrical wiring laid upon said rim, on opposite sides of the peripheral groove and radial slots.

15. In a dynamo-electric machine, a discoidal armature, and wires thereon formed with converging flat ends lying edgewise on the opposite sides of said rim.

16. A dynamo-electric machine coinprising a field-magnet having poles of annular form, a discoidal' armature arranged to-revolve' with its rim projected between said poles, the latter being sectioned superficially by in ersecting groovesrespectively concentrio with and tangential to the hub of the armature, and wires on the rim of the armature substantially radial to said hub.

17. A dynamo-electric machine compris-' ing an annular field-magnet, a centrally uncovered discoidal armature mounted therein, current conductors laterally disposed on the rim of said armature, concentric distributer and collector rings on both sides of the armature contiguous to the ends of said conductors, and correspondingly positioned brushes held in contact with said rings on ters and current collectors connected with opposite sides of the machine. 18. A dynamo-electric machine COIIIPIIS- mg an annular field-magnet, a centrally uncovered discoidal armature mounted thereing distributer and collector rings carried concentrically on opposite sides of the armature, current conductors on the armatures am having their ends connected each with one of said rings respectively, and oppositely located annular brushes held in contact with the several rings. 1

19. A dynamo-electric machine comprising a field-magnet, a discoidal armature therein, current conductors disposed laterally on the armatures rim, current distributhe ends of said conductors, brushes held in contact with said distributers and said 001- lectors, and means forefi'ecting individual adjustment of said brushes.

20. A dynamo-electric machine compr1s-.

ing an annular field-magnet, a discoidal armature mounted to revolve therein, said armature bein conductors disposed laterally on the armatures rim, distributer and collector rings respectively connected with the opposite" ends of said conductors, annular brushes in contact with said rings, and wire connections between said brushes and the terminals of the electric circuit. f

' 21. A dynamo-electric machine compris- 1n th rein, distributer and collector rings on opposite sides of said armature, current conductors on the armaturesri-m having their ends respectively connected with said rings, brushes in contact'with the latter, adjusting members for said brushes, and means exerting a yielding pressure on said adjusting centrally uncovered, current a field-magnet, a discoidal armatureaged by said suspending. means and operating to urge the brushes individually against.

the rings.-

23 A dynamo-electric machine comprising therein, distributer and collector rings on opposite sides of said armature, current con.-

said' rings, brushes in contact with the latter, said brushes being provided .with' external projections, longitudinally movable tubular a field-magnet, a discoidal armature,

ductors 'on the armatures rim having their opposite ends respectively connected with members engaging said projections, and

means normally pressing said tubular memhers-inward.

24. A dynamo-electric machine comprising an annular field-magnet, a discoidal ar mature mounted to revolve therein, current conductors disposed laterally on vthe arma-- tures rlm, current distributers and current collectors on both sides of the armature re spectively connected with the opposite ends of said conductors, brushes in'contact with said distributers and said collectors, adjust- .ing members for said brushes slidably supported on opposite sides of the field-magnet, tensioning devices adjacent to said adjusting members, and means whereby the adjusting members are brought under the influence of said devices.

25. A dynamo-electric machine comprising a field-magnet, a discoidal armature therein, distributer and collector rings on opposite sides of said armature, current conductors on the armatures rim having their ypaired brushes in contact with the latter, adjusting members for the several brushes slidabletoward and away from the fieldmagnet, spirally wound tensioning devices projecting outwardly from opposite sides of the field-magnet and wrapped around said adjusting members, and means connected ;with said devices whereby the adjusting members can be moved endwise.

26. A dynamo-electric machine comprising an annular field-magnet, a discoidal armature mounted to revolve therein, current conductors disposed laterally on the armatures rim, pairs of current distributers and of current collectors on the opposite sides of the armature respectively connected with the opposite ends of said conductors, paired brushes in contact with said distributers and said collectors, terminal rods following the curvature of the field magnet and wires respectively connecting the paired brusheswithsaid terminal rods.

27. A dynamo-electric machine comprising an annular field-magnet formed with opposed polar surfaces and a recess outwardly located with relation to the latter, a discoidal armature having an uncovered.central portion and a rim projected between said surfaces, current conductors laterally opposite ends connected with said rings,

disposed on said rim, current distributers at the inner ends of said conductors borderlng the uncovered portion of said armature, c111- rent collectors at the outer ends of the conductors Within said recess, and brushes arranged to contact respectively with said distributers and said collectors.

In testimony. whereof, I have signed my nameto this specification, in the presence of two subscribing Witnesses.

ALBERT AIE. STERZING.

Witnesses:

LESTER C. TAYLOR, FRED FORKE. 

